Many conventional valves have problems with flow stability. For example, electronically controlled valves conventionally include a coil or solenoid that, when energized, creates a magnetic field. This magnetic field induces a magnetic attractive force between a fixed pole piece and a movable armature, causing the armature to move toward the pole piece, thereby unblocking an opening and allowing fluid to pass. However, because the attractive force between the armature and the pole piece increases exponentially as the distance between them decreases, the fluid pressure can become unstable. It is therefore desirable to provide a valve with improved stability.